The FBI has arrested 74 scammers in a massive global email scam crackdown , the US Department of Justice (DoJ) announced on June 11. The scammers were arrested for their involvement in business email compromise (BEC) schemes, which involved attempts to steal both data and money from individuals and businesses.

The arrests were made thanks to the efforts of the six-month long operation, called Operation Wire Wire, which saw the DoJ, the FBI, the US Treasury department, the Department of Homeland Security (DHS), as well as the US Postal Inspection Service collaborate.

Of the 74 scammers apprehended, 42 were arrested in the US, 29 in Nigeria and 3 in Canada, Poland and Mauritius. US authorities also seized around $2.4 million and recovered nearly $14 million in fraudulent wire transfers. According to the the DoJ, BEC scams involve romance scams, rental scams, lottery scams, job opportunity scams and more.

These scams involve money mules, who may be either willing or unwitting accomplices in the crime. The money mules’ role involves receiving funds from the victims and transferring the money, following the scammers’ instructions. According to the DoJ, money mules are generally recruited via either “romance scams” or “work-from-home” scams.

In most cases, the money is either wired or sent by check to the mule, who then deposits it in his/her account, keeping a fraction of the funds as commission, before transferring the funds in the way instructed by the fraudsters.

“Local and state law enforcement partners on FBI task forces across the country, with the assistance of multiple District Attorney’s Offices, charged 15 alleged money mules for their role in defrauding victims,” the DoJ said in a statement. “ These money mules were employed by the fraudsters to launder their ill-gotten gains by draining the funds into other accounts that are difficult to trace.”

According to the DoJ’s official statement, several of the BEC cases that , which defrauded both small and big businesses saw international criminal organizations involved in the scams as well. BEC crimes, as well as crimes involved email account compromise (EAC), have seen the loss of around $3.7 million over the past few years.

“Fraudsters can rob people of their life's savings in a matter of minutes,” Attorney General Jeff Sessions said in a statement. “These are malicious and morally repugnant crimes. The Department of Justice has taken aggressive action against fraudsters in recent months, conducting the largest sweep of fraud against American seniors in history back in February. Now, in this operation alone, we have arrested 42 people in the United States and 29 others have been arrested in Nigeria for alleged financial fraud.”